Seroprevalencia de la Leishmaniasis Visceral Canina mediante Elisa con rK39 en Focos Endémicos de Venezuela / Seroprevalence of Canine Visceral Leishmaniasis by rK39-ELISA in Endemic Foci in Venezuela

En el presente trabajo se presenta la seroprevalencia de la leishmaniasis visceral canina (LVC), zoonosis causada por Leishmania infantum/chagasi. Se realizaron pruebas serológicas y examen clínico a 15.822 perros de 13 entidades federales endémicas para la leishmaniasis visceral en Venezuela, en el periodo 2004-2012. Los sueros fueron analizados mediante ELISA con el antígeno recombinante rK39. Los resultados muestran que 14,8% de la población de caninos son positivos para LV. Los estados Lara (19%) y Guárico (18%) mostraron una mayor prevalencia de la enfermedad. Sin embargo, para los años 2010-2012, la prevalencia de la LVC para las entidades federales como Anzoátegui, Aragua, Carabobo, Cojedes, Nueva Esparta y Sucre se mantuvieron entre un 3% y un 31%. Los caninos seropositivos (67,1% machos y 32,9% hembras) tenían edades promedio de 4,8±2,9 años. El 81% de los caninos seropositivos encontrados en estas zonas, no presentó signos clínicos característicos de LVC, mientras que la clínica presentada por el resto fueron ulceraciones cutáneas (8,5%), alopecia (9,4%) y onicogrifosis (19,2%). Este reporte muestra la distribución geográfica (tanto en zonas rurales como urbanas) y características clínicas más resaltantes de perros parasitados en las diferentes regiones endémicas del país, con el fin de tomar medidas estratégicas que fortalezcan los programas de control y prevención de esta zoonosis problema de salud pública.

This study discloses the seroprevalence of canine visceral leishmaniasis (CVL), a zoonotic disease caused by Leishmania infantum/chagasi. In this study, serological tests and clinical examinations were performed in 15,822 dogs from 13 federal entities endemic for visceral leishmaniasis in Venezuela, during the period 2004-2012. Serum samples were analysed by ELISA against the recombinant antigen rK39. Results demonstrated a prevalence of 14.8% of positive dogs for VL. Lara (19%) and Guárico (18%) states showed the highest seroprevalence of the disease. However, for the years 2010-2012, the prevalence of CVL for federal entities as Anzoátegui, Aragua, Carabobo, Cojedes, Nueva Esparta, and Sucre remained between 3% and 31%. The seropositive canines (67.1% males and 32.9% females) average 4.8±2.9 years of age and 81% of the dogs found in these endemic areas did not show clinical signs characteristic of LVC, while clinical symptoms presented by the rest were skin ulceration (8.5%), alopecia (9.4%) and onychogryphosis (19.2%). This report demonstrates the geographical distribution (both rural and urban) and most striking clinical features of parasitized dogs in different endemic regions of the country, in order to take strategic actions to strengthen the control and prevention programs of this public health problem.

Epidemiological aspects of human and canine visceral leishmaniasis in Venezuela.

OBJECTIVE: To report recent data on the distribution of human and canine visceral leishmaniasis (VL) in Venezuela, and to highlight problems associated with effective control measures. METHODS: We report the number of cases, incidence rate, age and sex distribution, and mortality rates for human VL (HVL) for the period of 1995 through 2000, based on National Registry of Leishmaniasis data. We carried out serological studies on a total of 3 025 domestic dogs from the 12 states in Venezuela reporting cases of human VL in this 1995-2000 period and also from the state of Yaracuy, where cases were reported earlier during the decade of the 1990s. RESULTS: From 1995 through 2000, 242 cases of HVL were reported from 12 states, in various sections of Venezuela. There was a relatively stable national incidence rate of 0.2 cases per 100 000 persons per year. Of the 242 cases, 26.0% were from Margarita Island, one of the three islands that make up the state of Nueva Esparta (Margarita Island was the only one of the Nueva Esparta islands that had HVL cases). Over the 1995-2000 period, the annual incidence rates for Nueva Esparta ranged from 1.7 to 3.8 cases per 100 000 population. Males in Venezuela were more frequently affected (59.5%) than were females (40.5%). In terms of age, 67.7% of the VL patients were

Epidemiological aspects of human and canine visceral leishmaniasis in Venezuela

OBJECTIVE: To report recent data on the distribution of human and canine visceral leishmaniasis (VL) in Venezuela, and to highlight problems associated with effective control measures. METHODS: We report the number of cases, incidence rate, age and sex distribution, and mortality rates for human VL (HVL) for the period of 1995 through 2000, based on National Registry of Leishmaniasis data. We carried out serological studies on a total of 3 025 domestic dogs from the 12 states in Venezuela reporting cases of human VL in this 1995-2000 period and also from the state of Yaracuy, where cases were reported earlier during the decade of the 1990s. RESULTS: From 1995 through 2000, 242 cases of HVL were reported from 12 states, in various sections of Venezuela. There was a relatively stable national incidence rate of 0.2 cases per 100 000 persons per year. Of the 242 cases, 26.0 percent were from Margarita Island, one of the three islands that make up the state of Nueva Esparta (Margarita Island was the only one of the Nueva Esparta islands that had HVL cases). Over the 1995-2000 period, the annual incidence rates for Nueva Esparta ranged from 1.7 to 3.8 cases per 100000 population. Males in Venezuela were more frequently affected (59.5 percent) than were females (40.5 percent). In terms of age, 67.7 percent of the VL patients were < 4 years of age, and 80.6 percent were younger than 15 years. The mortality rate among the persons with VL was 7.85 percent during the 1995-2000 period. Serological screening with rK39 antigen of 1217 dogs from Margarita Island found a 28.5 percent positivity rate (testing of dogs was not done on the two other islands of Nueva Esparta). In contrast, the rate was 2.8 percent in the 1 808 samples from dogs from 12 states on the mainland. CONCLUSIONS: Human and canine VL are unevenly distributed in Venezuela. The distribution may reflect such factors as differences among the states in human population density, vector density, and the presence or absence of other trypanosomatidae. Particularly high infection rates in very young children as well as in domestic dogs occur in semiurban communities of Nueva Esparta, where other human-infecting trypanosomatidae have not been reported. Control measures related to limiting canine infection might contribute to disease control where VL infections are frequent. Reducing VL mortality requires increased awareness among medical professionals of the possibility of VL in the differential...

Epidemiological and immunological aspects of human visceral leishmaniasis on Margarita Island, Venezuela

Sixty-five patients were diagnosed with visceral leishmaniasis (VL) on Margarita Island in the decade from 1990 to1999; 86.2 percent were <= 3 years old. All were leishmanin-negative at diagnosis. Evaluation of 23 cured patients in 1999 revealed that 22/23 had converted to leishmanin-positive; five had persisting antibodies to rK39 antigen, with no clinical evidence of disease. Leishmanin tests were positive in 20.2 percent of 1,643 healthy individuals from 417 households in endemic areas. Of the positive reactors, 39.8 percent were identified in 35 (8.4 percent) of the households, 15 of which had an antecedent case of VL, a serologically positive dog or both. Weak serological activity to rK39 antigen was detected in 3 of 488 human sera from the endemic areas. The presence of micro-foci of intense peri-urban transmission and the apparent absence of other Trypanosomatidae causing human disease offer a unique opportunity for the study of reservoirs, alternative vectors and evaluation of control measures on the Island

Epidemiological and immunological aspects of human visceral leishmaniasis on Margarita Island, Venezuela.

Sixty-five patients were diagnosed with visceral leishmaniasis (VL) on Margarita Island in the decade from 1990 to1999; 86.2% were <= 3 years old. All were leishmanin-negative at diagnosis. Evaluation of 23 cured patients in 1999 revealed that 22/23 had converted to leishmanin-positive; five had persisting antibodies to rK39 antigen, with no clinical evidence of disease. Leishmanin tests were positive in 20.2% of 1,643 healthy individuals from 417 households in endemic areas. Of the positive reactors, 39.8% were identified in 35 (8.4%) of the households, 15 of which had an antecedent case of VL, a serologically positive dog or both. Weak serological activity to rK39 antigen was detected in 3 of 488 human sera from the endemic areas. The presence of micro-foci of intense peri-urban transmission and the apparent absence of other Trypanosomatidae causing human disease offer a unique opportunity for the study of reservoirs, alternative vectors and evaluation of control measures on the Island.